Configure validation of ROCA-vulnerable WHfB keys during authentication
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Policy overview

Key metadata and intent for this policy.

Computer
Category
System > Security Account Manager
Supported on
At least Windows Vista

Supported OS tags: Windows10, Windows10RT, Windows11, Windows7, Windows8, Windows81, WindowsRT, WindowsRT81, WindowsServer2008, WindowsServer2012, WindowsServer2012R2, WindowsServer2016, WindowsVista

This policy setting allows you to configure how domain controllers handle Windows Hello for Business (WHfB) keys that are vulnerable to the "Return of Coppersmith's attack" (ROCA) vulnerability. For more information on the ROCA vulnerability, please see: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-15361 https://en.wikipedia.org/wiki/ROCA_vulnerability If you enable this policy setting the following options are supported: Ignore: during authentication the domain controller will not probe any WHfB keys for the ROCA vulnerability. Audit: during authentication the domain controller will emit audit events for WHfB keys that are subject to the ROCA vulnerability (authentications will still succeed). Block: during authentication the domain controller will block the use of WHfB keys that are subject to the ROCA vulnerability (authentications will fail). This setting only takes effect on domain controllers. If not configured, domain controllers will default to using their local configuration. The default local configuration is Audit. A reboot is not required for changes to this setting to take effect. Note: to avoid unexpected disruptions this setting should not be set to Block until appropriate mitigations have been performed, for example patching of vulnerable TPMs. More information is available at https://go.microsoft.com/fwlink/?linkid=2116430.

Internal name
SamNGCKeyROCAValidation
Policy ID
8907e1c684ac
Elements
1

Registry values

How enabled and disabled states update the registry.

No explicit registry values are set for enabled or disabled states.

Policy elements

Inputs and configuration options exposed by this policy.

ScopeElementTypeRegistry mappingConstraints & behaviorCopy
Computer
Options for handling ROCA-vulnerable WHfB keys:
ID SamNGCKeyROCAValidation_Settings
enum
Path
Software\Microsoft\Windows\CurrentVersion\Policies\System\SAM
Value name
SamNGCKeyROCAValidation
Type
REG_DWORD
Options: Ignore ROCA-vulnerable WHfB keys (0), Audit ROCA-vulnerable WHfB keys on use (1), Block ROCA-vulnerable WHfB keys on use (2)
Options for handling ROCA-vulnerable WHfB keys:
Computer · Type enum
Registry mapping
Path
Software\Microsoft\Windows\CurrentVersion\Policies\System\SAM
Value name
SamNGCKeyROCAValidation
Type
REG_DWORD
Details
Options: Ignore ROCA-vulnerable WHfB keys (0), Audit ROCA-vulnerable WHfB keys on use (1), Block ROCA-vulnerable WHfB keys on use (2)